Cleaning device for rotary printing machine



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CLEANING DEVICE FOR ROTARY PRINTING MACHINE Filed Sept. 28, 1954 4 Sheets-Sheet 3 I v 0);; E FIG.-6

JEN/10R; d mam E Wa -Tom ME Y/ April 29, 1958 L. F. MITCHELL ETAL 2,832,289

CLEANING DEVICE FOR ROTARY PRINTING MACHINE Filed Sept. 28, 1954 4 Sheets-Sheet 4 i M 59 a w 60 United States liatent O CLEANING DEVltClE FER ROTARY PRINTING MACHENE Lester F, Mitchell, dhaker Heights, and Edward J. Janka,

Qleveland, (Ulric, assignors to Addressographdlilnlth.

graph Corporation, Eleveland, Ohio, a corporation of Delaware Application September 28, 1954, Serial No. 458,738

8 Qlairns. (\Cl. Mil-425) machine and then makes the required number of imprints thereform, following which he removes such printing plate and repeats the operation for successive printing plates. Before imprints can be made from a second plate the transfer surface of the olfset or transfer cylinder must be cleaned by the operator. This has been a time consuming operation which materially reduces the output of the machine.

in the past various mechanical devices have been proposed for cleaning such offset surfaces. However, such devices were either inefficient in their cleaning operation, or their use resulted in substantially no saving of time. Accordingly such devices as have been proposed in the past are not in general use at the present time. Therefore, a more specific object of the present invention is to provide a cleaning device for cleaning the surfaces of the offset or transfer cylinder of a rotary planographic printing or duplicating machine which will efiiciently clean such surface with a minimum time loss.

Another object of the invention is to provide an offset blanket cleaning device which may be attached as a unit to existing rotary planographic printing machines.

At the present time the transfer surfaces of planographic printing machines generally are cleaned manually. To accomplish this the machine is stopped, and the offset blanket wiped with a cloth which has been moistened an in a cleaning solution. Such operations are slow, especially in ofdce printing or duplicating machines Where only a relatively small area of the transfer surface is accessible. In such instances the accessible area must be cleaned, the machine operated to make an adjacent area accessible, and the cleaning operations repeated until the entire transfer surface has been cleaned. Such operations not only take considerable time, but in addition effective cleaning requires the use of a volatile ink solvent. The cleaning cloth, which is more or less saturated with such solvent, presents objectionable odors and is hazardous. Accordingly an object of the present invention is to provide a cleaning device for cleaning inked surfaces of the cylinders of rotary planographic ofiice printing or duplicating machines which device will enable the use of volatile cleaning fluids and at the same time reduce to a minimum the hazards and objectionable odors associated therewith.

Other objects and advantages of the invention will be come more apparent from the following description relating to a preferred embodiment of the invention, which is illustrated in the accompanying drawings, in which:

2,332,289 Patented Apr. 29, 1958 ice Fig. l is a perspective view of the improved cleaning device in position on a rotary planographic printing or duplicating machine, a portion only of such machine being illustrated;

Fig. 2 is a perspective view of the device shown in Fig. 1 looking from substantially the opposite direction;

Fig. 3 is vertical section through the cleaning device, the plane of the section being indicated by the lines 3-3 on Figs. 1, and 6;

Fig. 4 is a substantially horizontal section, the plane of which is indicated by the lines 4-4- on Figs. 1 and Fig. 5 is a vertical section, the plane of which is indicated by the lines 5-5 on Figs. 3 and 4;

Fig. 6 is a vertical section taken in a plane parallel to that of Fig. 5 and is indicated by the lines 6-6 on Figs. 3 and 4;

Fig. 7 is a fragmentary vertical section, the plane of which is indicated by the lines 7-'7 on Fig. 6; and

Fig. 8 is a sectional detail, the plane of which is indicated by the lines li-8 on Fig. 6.

Referring now to the drawings, a rotary planographic printing or duplicating machine is generally indicated at ill in Figs. 1 and 2. The portion of the: machine, there shown, include a pair of spaced end frame members 11, between which the usual planographic printing cylinders are rotatably mounted. Such cylinders generally comprise a master or pattern cylinder about which the usual planographic printing plate is removably positioned in the usual manner, an oifset or transfer cylinder 16 which carries a relatively thin transfer or offset blanket l7 generally composed of a rubber covered fabric about one-sixteenth of an inch in thickness and having a smooth rubber outer surface to receive the inked image from a printing plate on the master cylinder 15 and to transfer such image to a work sheet which is fed, for instance, by feeding tapes 19 into the bite of the transfer roll and a suitable coacting platen or impression roller (not shown). Such machines are provided with suitable inking and ink repellent applicator mechanisms, and are generally power driven. Planographic printing machines of this type, and the principles of their operation are well known in the art at the present time.

The cleaning device, with which the present invention is particularly concerned, is generally indicated in Figs. 1 and 2 at Bil. As there shown such device includes a main frame 21 having a pair of end plates 22 spaced apart by suitable cross frame members 23 and 24. Each end plate 2-2 has a bracket or car 25 by means of which the device may be attached to the frame plates 11 of a printing machine as, for instance, by bolts 26. Pivotally mounted between the frame plates 22 of the frame structure 21 is a supplemental frame including a pair of end plates 32 which are spaced apart by a suitable frame member such as that shown at 33. The supplemental frame 3% is pivotally mounted on a shaft 35 the ends of which are secured by bolts 36 to respective end plates 22 of the main frame structure 20.

The ink remaining on the offset or transfer blanket 7.3, following the making of the desired number of impressions is removed by a rubber covered cleaning roll 4d. This roll is rotatably mounted on a shaft 41 which is secured to the supplemental frame plates 32 by suitable studs 42.

The supplemental frame St; is movable about its pivot shaft 33 so that it may be rocked to bring the cleaning roll 46 into and out of rolling contact with the offset blanket 17. This is accomplished by means of a manually operable lever 43 which is pivotally mounted as at 44 to the cross frame member 23 of the main frame 20. The inner end of this lever is provided with, a cam slot 45 which coacts with a pin 46 carried by the cross frame member 33 of the supplemental frame. The arrangement is such that, as the handle 47 f the lever 43 is swung from one side to the other, the supplemental frame 30 will be rocked about its pivot rod 35 to move the cleaning roll 4i into and out of rolling'engagement with the offset blanket 17 carried by the offset cylinder 16. Iii-Fig. '5 the cleaning roll at) is shown in its inactive or idle position by full lines, and is indicated in its active or blanket engagement positionby dot-and-dash lines 7.

The supplemental frame 39 is normally tensioned to ward its idle position by a pair of springs 51 positioned at opposite ends of the device. Each spring is interconnected between a pin 52 carriedby a supplemental frame plate 32 and a pin 53 carried by a main frame plate 22.

The pressure between the cleaning roll as and the offset blanket 17 is controlled by adjustment of the pivotal connection 44 between the lever 43 and the frame member 23. This pivotal connection is best shown in Fig. 8 where it will be seen that such pivot comprises a pin 48 having an eccentrically extending stud or threaded portion 45 which extends through the frame member 22. The pin 48 is clamped in the desired adjusted position by a nut 50. When it is desired to change the pressure between the offset blanket and the cleaning roll 4th the nut t) may be loosened and the pin 4% turned to swing the supplemental frame 30 in the desired direction.

The cleaning roll 44) is rotated solely by its frictional contact with the oifset blanket 17 and is reciproca-ted axially of its supporting shaft 41 as it is rotated to thereby insure proper transfer of all of the ink from the offset blanket 17 to the roll 40 by causing a slight wiping action therebetween. This reciprocation is caused by a cam groove 56 formed in one end of the roller and engaged by a pin 58 carried by a stationary block 59 secured to the right hand frame plate 32. The cam groove 56 is so shaped that reciprocation of the roller occurs as a result of its rotation.

The ink transferred to the cleaning roller db is removed therefrom by a cleaning fluid or solvent and a wiper blade.

As shown in the drawings a supply of cleaning fluid 12 is stored in a pan or container 6b which is removably mounted on the lowermost frame member 24 of the main frame 20. The container 66 comprises an elongated rectangular substantially enclosed pan having an elongated slot 61 in its upper surface into which a roller 62 projects. The roller 62 comprises a relatively small metal roll rotatably mounted between a pair of brackets 63 which are pivotally connected on a cross bar 64,, the ends of which are rotatably mounted in the supplemental frame plates 32.

tained in this position by a counterweight provided by a cross rod 64 carried by rearwardly extending arms 65 of the brackets 63. The counterweight is such that a relatively thin film of cleaning fluid or ink solvent remains on the surface of the cleaning roller 40 after it passes the roller 60. This film together with any ink remaining on the roller 40 is removed by a wiper blade 70.

,The wiper blade 70 is secured to the bar 64 and is pressed'against the periphery of the cleaning roller 40 by a threaded stud 7f carried by a lever '72 which is pivotally secured as at '73 to the frame member 33 of the supplemental frame 36. The stud 71 engages a pressure plate 74 which is secured to the bar 64 by certain of the screws '75 which also serve to secure the Wiper blade 70 thereto. The pressure of'the wiper blade 7% on the cleaning roll 40 is controlled by adjustment of the stud 71 in the usual manner. it will be noted that the wiper blade 7 fl is tangent to the surface of the roll 40 and extends some distance beyond its point of tangency so that it removes ink and cleaning'fiuid from the roll 4- by a wiping action rather than by a scraping action. This facilitates the use 4. of a cleaning roll having arelatively soft surface as the wiping action together with the axial movement of the roll prevent damage to the surface thereof.

As heretofore mentioned the roller 62 applies a relatively thin coating of cleaning fluid or ink solvent to the cleaning roll 40. This coating may be transferred directly to the offset blanket 17 by removing the pressure of the wiper blade 70 on the roll W This is accomplished by manually swinging the lever 72 about its pivot 73, from the full line position shown in Fig. 7 to the dotted line position therein shown. For this purpose the lever 72 extends some distance upward from the cleaning device to enable it to be readily grasped by the operator. A spring detent 76 is mounted on a block 77 which is secured to the frame member 33 of the supplemental frame and engages the lever 72 serving to retain it in either of its extreme positions.

The cleaning fluid container 60, as heretofore mentioned, may be removed readily. When in position, this container rests on the shelf-like cross member 24 of the frame structure 20 with its forward edge against upturned stops 8%) (Figv 6), and is retained in such position by a spring catch 81 pivotally connected to the member 24 as at $2. To remove the container 60, the catch 81 is depressed and swung from the full line position, shown in Figs. 4 and 5, to the dotted line position therein shown, and the container then slid rearward. As the container 66 is removed the inturned lip 83, at the forward edge thereof, engages the roller 62 rocking the latter out of the container into the dot-and-dash line position shown in Fig. '5. When the container is to be replaced the operator grasps the counterweight 66 and again rocks the roller 62 to move it from the path of the container permitting it to drop into the slot 61 as the container is moved into position.

When it becomes desirable to clean the offset blanket 17, the operator swings the handle 47 to bring the cleaning roll into contact with the offset blanket with the tension on the wiper blade 70 released. The offset drum is then rotated, either manually or by power in the direction of the arrow of Fig. 2, thereby transferring a thin film of cleaning solution 112 from the container to the blanket 17, following which the lever 72 is swung to tension the wiper blade against the cleaner roll, whereupon the solvent laden ink is transferred to the surface of the cleaning roll from which it is removed by the tensioned wiper blade 70. It has been found that a rubber cleaning roll having a Shore A durometer reading of from three tenths to six tenths that of the reading of the offset blanket with which it is used provides a highly efficient cleaning device, particularly when used with a metal surfaced solvent applicator roll.

While the cleaning roller 40 has been described as comprising a rubber covered roll and the offset blanket 17 has been described as a rubber coated fabric it is to be understood that the term rubber includes rubber compositions, synthetic rubber compounds, and other commercial materials used as rubber substitutes.

We claim:

1. In a cleaning device for removing ink from the surface of a rotary printing machine drum, a main frame adapted to be mounted on a printing machine, a supplemental frame movably mounted therein, a cleaner roll rotatably mounted in the supplemental frame with its axis parallel with the axis of the drum, manually operable means to move the supplemental frame to move said roll into and out of frictional driving engagement with the drum surface, means to apply a film of liquid ink solvent to said roll, said last mentioned means including a solvent applicator member coacting between a supply of the liquid ink solvent and said roll and engaging the latter, a wiper rriovably mounted in said supplemental frame and being spaced from said applicator member in the direction of rotation of said roll, and means under control of the operator to selectively press said wiper into engagement with said roll to prevent further transfer of solvent to the drum surface and to remove ink and solvent from said roll whereby the roll presents a clean dry surface to the drum, or to so coact with said roll as to permit a thin film of solvent to remain on the roll and be transferred to the surface to be cleaned.

2. In a device for cleaning the offset surface of a rotary printing machine cylinder, 21 frame adapted to be secured to the printing machine, a rubber covered roll rotatably mounted in said frame and movable bodily to and from frictional driving contact with the surface to be cleaned, a receptacle for liquid ink solvent, a carriage pivotally mounted in said frame, a roller journaled in said carriage and having a portion of its surface submerged in said solvent, yielding means normally acting to retain the carriage in a position wherein said roller is in contact with said roll, a wiper blade mounted on said frame and normally positioned relative to said roll as to permit a fiilm of solvent applied thereto by said roller to pass to the offset surface, and manually operable means to press the wiper into engagement with said roll to remove all solvent or solvent laden ink therefrom and cause such roll to present a clean dry surface to the offset surface.

3. In a device for cleaning the transfer surface of a rotary printing machine drum, a frame, a rotatable rubber covered roll movably mounted in said frame, manually operable means to bodily move said roll to and from frictional contact with the transfer surface to be cleaned, means to adjust the pressure of said roll against the transfer surface, means carried by said frame to supply said roll with a liquid ink solvent, a movably mounted spring metal wiper blade carried by said frame and having a substantially flat surface adapted to tangentially extend across and engage the surface of said roll to remove ink solvent therefrom, and manually operable lever carried by said frame and adapted to coact with said wiper means to retain said lever in either of two positions in one of which said wiper is positioned to permit a thin film of liquid to pass between the wiper and said roll surface for transfer to the surface of the drum to be cleaned and in the other position to cause said wiper to remove all solvent or solvent laden ink from the roll and cause the roll to present a clean dry surface to the drum surface to be cleaned.

4. In a device for cleaning ink from the surface of a rotary printing machine drum, a main frame adapted to be secured to a printing machine, a supplemental frame pivoted to the main frame, a rubber covered roll rotatably mounted in the supplemental frame, manually operable means including a cam interposed between said frames to swing the supplemental frame and move said roll into and out of frictional contact with the surface to be cleaned, a container for ink solvent mounted in said main frame, a carriage pivotally mounted in said supplemental frame, a rotatable hard surfaced roller mounted in said carriage and partially submerged in such solvent, yielding means normally acting on said carriage to retain said roller in frictional contact with said roll, a resilient wiper blade pivotally mounted in said supplemental frame and having a substantially flat surface adapted to tangentially engage said roll to remove solvent therefrom, and manually operable member interposed between said supplemental frame and said member and movable to either of two positions in one of which the wiper is tensioned against said roll with suflicient pressure to remove all solvent therefrom whereby said roll presents a clean dry surface to the drum surface to be cleaned and in the other of which positions the pressure of the wiper on the roll is relieved sufiiciently to permit a thin film of solvent to remain on said roll and be presented to the surface to be cleaned.

5. In a device for cleaning the offset blanket of a rotary printing machine cylinder, a frame adapted to be secured to the printing machine, a supplemental frame movably mounted therein, a relatively soft surfaced roll rotatably mounted in said supplemental frame and movable axially relative thereto, manually operable means to move the supplemental frame to move said roll into and out of frictional contact with the printing machine blanket, a receptacle for fluid ink solvent, a roller rotatably mounted in said supplemental frame and movable bodily to and from said roll and having a portion of its surface submerged in said solvent, a counterweight connected to retain said roller in contact with said roll and in such fluid, a wiper pivotally mounted in said supplemental frame and swingable to and from said roll, said wiper having flat portion thereof adapted to tangentially engage said roll, a manually operable member mounted on said supplemental frame and adapted in one position to engage and to swing said wiper about its pivot to tension said wiper against said roll to remove all solvent therefrom and thereby cause said roll to present a dry clean surface to the blanket, adjustable means carried by said member to control the tension applied to the wiper thereby, said member being movable to a position to disengage said wiper to release said tension and permit a thin film of solvent to pass between the wiper and said roll and be 0 applied to the blanket to soften ink thereon.

6. In a cleaning device for removing ink from a cylindrical transfer surface of a rotary printing machine, a frame adapted to be mounted on the printing machine, a roll rotatably mounted in said frame for engagement with the cylindrical surface to be cleaned, a container for a fluid ink solvent slideably mounted in said frame for removal therefrom, a roller mounted in said frame for movement into and out of said container and having a portion of its periphery normally submerged in ink solvent carried by said container and having another portion of its periphery in engagement with said roll, and means on the container engageable with the roller to move said roller out of the container consequent upon removal of the container from said frame.

7. In a cleaning device for removing ink from a cylindrical transfer surface of a rotary printing machine, a frame adapted to be mounted on the printing machine, a relatively soft surfaced roll rotatably mounted in said frame and bodily movable relative thereto into and out of frictional contact with cylindrical surface to be cleaned, a manually operable came to selectively move said roll, a container for a fluid ink solvent slidably mounted in said frame for removal therefrom, a relatively hard surfaced roller mounted in said frame and bodily movable into and out of said container and adapted to have a portion of its periphery in the solvent carried by said container and another portion of its periphery in frictional engagement with said roll, means carried by said frame to remove ink laden solvent from said roll, means to reciprocate said roll axially consequent upon its rotation, yielding means acting to retain said roller in said container, and means carried by the container to move said roller out of the container consequent upon removal of the container from said frame.

8. In a device for cleaning ink from the offset blanket of a rotary printing machine cylinder, a frame adapted to be secured to the printing machine, a rotatable rubber covered roll journalled in said frame and adapted to be moved bodily to and from frictional driving contact with the surface to be cleaned, means associated with said frame to move said roll into frictional contact with the offset blanket to be cleaned, a receptacle for ink solvent mounted beneath said roll, a second roll having its axis substantially parallel to the rubber covered roll, and having a portion of its surface submerged in said solvent and another portion thereof in rolling contact with the first-mentioned roll, the line of contact between the two rolls being disposed above the level of the solvent in the the receptacle'and"to' depoSit 'itnpon the first-namedroll,

means for supporting these'cond narned roll in rolling contact with the first-named roll during its movement into and Whileengaging the surface to be ,cleaned, and means on 'at least one of said rolls for reciprocating it while the first-mentioned roll is in rolling contact with the surface to be cleaned.

References {liter in the file of this patent UNITED STATES PATENTS 'Cottrell I an. 2, 1894 Crump 'Sept.' 21,1915 Goulding May -10, 1927 Curtis Nov. 17, 1942 Larsen Dec. 23, 1952 Gullixson et a1 -Nov. 24, 1953 

